This is a hack of Vs. Super Mario Bros. that allows the game to be run on a standard MMC1 cart with 8KB SRAM. (MMC1 was used because no official CNROM carts support SRAM, not all emulators support this configuration, and MMC1 repro boards are cheap.) No custom hardware required!

It also adds the following features:

- Pre-game menu that allows you to set dipswitches and reset the high scores
- High score retention (when using battery-backed SRAM)
- Correct NES colors (Vs. hardware used RGB PPUs with scrambled colors)

This patch works with either of the commonly-available Vs. Super Mario Bros. iNES ROMs; the only difference between the two is the timer speed (see the readme for details).

This patch has been tested on the PowerPak and works without issue. It should also work on any other flash cart or copier with MMC1 support.

I might do more in the future, I'm not sure yet. This was kind of a harrowing ordeal at times, in part because my hacking skills are pretty rusty. The mapping logic in particular made me want to rip my hair out a few times; I was all ready to release this as CNROM, until I discovered that Nintendulator and some versions of FCEUX don't support SRAM with this board type, and the PowerPak exhibited random crashes/SRAM corruption on reset. It took me most of last night to learn how the MMC1 works and convert all the CNROM bankswitching code to its MMC1 equivalent (though it also gave me time to add a couple more features, one of which is [REDACTED]).

I haven't played much, but wasn't Excitebike given an official FDS conversion (though only a Disk Writer release, so I'd imagine it's pretty rare now).
(I know VS. Cluclu Land was also released on FDS, containing different levels than the cart version, along with an Expert Mode.)
What was different about Ice Climber?

Vs Ice Climber had a lot of stuff added. Wind physics would occasionally appear in some stages, and there was a new spear wielding bee enemy that would fly in from the sides of the screen. The game featured 24 extra levels in addition to the ones from the home version. These levels have a different palette to the regular stages, and they are much harder. Think to Ice Climber what Super Mario Bros 2 Japan was to SMB. The condor is replaced with a butterfly at the top of these stages, that moves in a wavy fashion. There's also a bonus round every few stages.

The Disk System version has most of the extras from Vs. For whatever reason, Nintendo replaced the bee and the butterfly with duplicate graphics of the bird enemy and the condor.

The Vs games have a lot of interesting changes. Its a pity these aren't that well documented. Some other additions off the top of my head.

Clu Clu Land: A new boss unira enemy was added. Its a giant version of the urchin enemies. Appears if you kill every urchin in the stage. Despite its size its killed in the same fashion as the regular enemies. This version was ported to the FDS.

Balloon Fight: Very different. Stages are twice as large, actually having the screen scroll upwards. Two player mode makes use of dual screens.

Pinball: On the bottom screen if you make 3 pink chicks appear instead of yellow ones and lose a ball, a strange winged creature, that looks an awful lot like the Clu Clu Land character, shows up and restores it.

Duck Hunt: Has that bonus round where you can shoot the dog, though you're not supposed to. The ducks graphics have also been changed being made smaller and harder to hit. You also proceed through the levels alternating between the two modes, first a duck stage, then a clay pigeon stage, then a bonus round, duck stage, etc.

Gumshoe: Starts off with harder enemies from the second wave in the home version. There's also graphics in the rom for some kind of gangster enemy, that was not present at all in the rom of regular Gumshoe. But I didn't see this character at any point playing the game.

Hogan's Alley: Like Duck Hunt, this has you proceeding through levels alternating between the game modes. However there isn't a brand new bonus round. Game C where you shoot cans in the air is now considered a bonus round. If you play the game long enough you can see an intermission screen that shows the professor target coming to life, attempting to sneak past the gangster targets, then getting shot at and fleeing. This was the only one in the game it seemed.

Mach Rider: Not terribly different, but a cool close up picture of Mach Rider appears before the start the game.

Wrecking Crew: Very very different from the regular game. Its a head to head game, where two players compete to demolish the building. It uses two screens with the opponent being presented as being on the other side of the background on their respective screen. Opposite of Balloon Fight, the levels don't scroll up in this one. Also an enemy type unique to this version shows up around the 14th or so stage. It looks like a walking hammer.

Am,most forgot. I made a cart copy of BB2 about 9 years ago, and it got sold off somewhere along the line. FYI if you ever see it around with a fairly cheap label of the title screen, its probably mine. I hope the current owner gets his ass beat by that game too!

great writeup. touching base on something you mentioned in the article, i remember a while back that on youtube there used to be some really crazy street fighter 2 fan made vids from japan, presumably from SF clubs that people made. real weird stuff like dip switch weirdness and crazy glitch maneuvering while still being competitive and keeping some semblance of gaming.

one of the vids i saw was ~20 minutes in legnth, certainly from nth generation vhs, from some weird fan group and really crazy. do you or anybody have any recollection of these kind of vids? i meant to download em at some point, and i guess at whatever point i went back into my favorites and the vids were deleted, certainly the titles for the vids were in japanese and i just happened to stumble upon em. ring any bells for anybody?